Monday

January 26, 2015

January 26, 2015

Posted by **Lisa** on Monday, July 22, 2013 at 3:55pm.

- Trig -
**Steve**, Monday, July 22, 2013 at 4:52pm17sec^2θ - 15secθ tanθ - 15 = 0

15secθ tanθ = 17sec^2θ - 15

225 sec^2θ tan^2θ = 289sec^4θ - 510sec^2θ + 225

225sec^4θ - 225sec^2θ = 289sec^4θ - 510sec^2θ + 225

64sec^4θ - 285sec^2θ + 225 = 0

That's just a quadratic in sec^2θ, so just solve it and you have your solution candidates.

However, because we squared things, there may be spurious solutions, so you have to check the values in the original equation.

In radians, I get .159,1.000,2.141,2.982

- Trig -
**Reiny**, Monday, July 22, 2013 at 5:01pm17sec2 θ − 15tanθsecθ − 15 = 0

17/cos^2 Ø - 15(sinØ/cosØ)(1/cosØ) - 15 = 0

times cos^2 Ø

17 - 15sinØ - 15cos^2 Ø = 0

17 - 15sinØ - 15(1 - sin^2 Ø) = 0

15sin^2 Ø - 15sinØ + 2 = 0

sinØ = (15 ± √105)/30

sinØ = .158435 or sinØ = .841565

Ø = 9.1° or 170.9° or Ø = 57.3° or 122.7°

**Answer this Question**

**Related Questions**

Trig - Use a calculator to find θ to the nearest tenth of a degree, if 0° &...

Complex angles - There are four complex fourth roots to the number 4−43&#...

Trigonometry - There are four complex fourth roots to the number 4−4√...

Trigonometry - Solve for θ in the equation cos θ = -0.181 when 180º &...

Trig - Given that csc θ = -4 and tan θ > 0, find the exact value of...

Algebra - Find the complete solution of each equation. Express your answer in ...

Algebra - Find the complete solution of each equation. Express your answer in ...

trig - Question #1 Suppose that θ is an angle in standard position whose ...

Trig - Verify the given equations: ____1______ + ____1_______ = -2 tanθ tan...

Math - Calculus - The identity below is significant because it relates 3 ...